Mexican troops arrest 2 in killing of U.S. border agent

U.S. Customs and Border Protection agent Nicolas Ivie, 30, was shot to death Tuesday near the U.S.-Mexico border in Arizona. NBC's Brian Williams reports.

By NBC News and wire services

Updated at 8:20 p.m. ET: MEXICO CITY -- Mexican troops have arrested two suspects in the killing of a U.S. Border Patrol agent and the wounding of a second officer in Arizona, Mexican security officials said on Wednesday.

The two suspects were detained in a Mexican military operation in the city of Agua Prieta, in Mexico's northern Sonora state, a few miles from the spot where Nicholas Ivie was shot dead early on Tuesday while responding to a tripped ground sensor, a Mexican Army officer, who declined to be named, told Reuters.

Ivie was among three agents who were patrolling on foot about five miles north of the international border when gunfire erupted. A second agent was also wounded while the third, a woman, was unharmed.

The agents had been patrolling in an area near the border town of Naco, well-known as a corridor for smuggling, and the Cochise County Sheriff's department has said that tracks were found heading south after the shooting.

Ivie was a 30-year-old father of two who grew up in Utah and was active in the Mormon Church. He had been an agent for four years.

A Mexican police official in Naco, across the border from the Arizona town of the same name, confirmed the arrests, which occurred in the early hours of Wednesday.

U.S. officials refused to comment on the report of the arrests to NBC News.

It was the first fatal shooting of an on-duty Border Patrol agent since December 2010, when Brian Terry was killed in a shootout with bandits near the border. Terry's shooting was later linked to the government's "Fast and Furious" gun-smuggling operation, which allowed people suspected of illegally buying guns for others to walk away from gun shops with weapons, rather than be arrested.

Two Border Patrol agents were killed last year in an accident during a car chase with smugglers near Phoenix.